U.S. Pat. No. 4,290,595 describes a rotatable advance gripper drum assembly for sheet-fed rotary printing presses. This assembly has an advance gripper drum and a gripper bridge movable relative to the drum, including a crank-driven linkage transmission device which is disposed on and rotatable with the drum and operatively connected to the gripper bridge for moving the gripper bridge.
U.S. Pat. No. 4,629,175 purports to show a method and apparatus for the stream-fed delivery of sheet-like products. Sheet-like products coming out of a folding apparatus are first transported some distance before being caused to overlap. To provide a regular feed stream arranged without damage to the products, the products are engaged on a support by grippers that are moved along a preferably arcuate path, in the course of which the products are slowed down by the grippers to the speed of a delivery belt, whereon the products are then deposited. This solution does not refer to deviation of sample signatures or the like.
U.S. Pat. No. 5,141,221 describes a deceleration device in a folder of a rotary printing press. A deceleration device for folded products conveys folded products one behind the other while being gripped by decelerable transport devices. The oppositely arranged decelerable transport devices are driven by a planetary gearing. While planetary gears rotate around a sun gear, an instantaneous center describes a cardioid which, via drive brackets, causes the transport devices to take different speeds during rotation of the planetary gears. This disclosure does not describe or suggest a deviation of sample signatures or sample folded products.
U.S. Pat. Nos. 5,249,493 and 5,427,005 describe devices for extracting samples from a folder. These devices include a pair of cutting cylinders including a blade cylinder and a grooved cylinder, the blade cylinder having at least one cutting blade mounted on the periphery thereof, the grooved cylinder having at least one groove bar, a respective holding device for signatures assigned to the groove bar, conveyor tapes for conveying signatures emerging from the nip between the blade cylinder and the grooved cylinder of the cutting cylinder pair to a signature delivery and to a conveyor unit assigned to the cutting cylinder-pair and a device for remotely controlling the holding devices. The devices for extracting samples disclosed in these two patents are assigned to the pair of cutting cylinders for immediately seizing a folded product. The devices are actuated mechanically, pneumatically or through solenoids.
In order to inspect a sample signature coming from a printing press, press operators generally grab the signatures from the shingled stream at the folder delivery. This can cause a disruption of the shingled stream and, in turn, cause problems in the downstream equipment.